Fungal Diseases
- Botrytis bunch rot (grapevine): Causes gray mold on berries, leading to rotting and spoilage.
- Downy mildew (grapevine, potato): Forms yellow or brown lesions on leaves and stems, causing defoliation and reduced yield.
- Fusarium head blight (cereals): Infects ears of wheat, barley, and corn, producing a toxic substance that can contaminate grain.
- Powdery mildew (many plants): White or gray powdery growth on leaves, stems, and flowers, reducing photosynthesis and growth.
- Rust (cereals, beans): Forms rusty-colored spores on plant surfaces, damaging leaves and stems.
Bacterial Diseases
- Bacterial blight (rice): Causes wilting and yellowing of leaves, leading to reduced yield.
- Bacterial wilt (cucumber, tomato): Blocks water flow through the plant, causing wilting and yellowing.
- Crown gall (many plants): Causes the formation of tumors on roots or stems, disrupting nutrient and water transport.
- Fire blight (apple, pear): Kills blossoms, shoots, and branches, resulting in reduced fruit production.
- Soft rot (potato, carrot): Causes the decay and rotting of stored produce.
Viral Diseases
- Tomato spotted wilt virus (many plants): Symptoms vary by plant, including leaf bronzing, wilting, and fruit distortion.
- Tobacco mosaic virus (tobacco, tomato): Causes mottling and distortion of leaves, reducing yield.
- Cucumber mosaic virus (cucumber, squash): Produces a mosaic pattern on leaves, stunting growth and reducing yield.
- Potato virus Y (potato): Causes yellowing and wrinkling of leaves, reducing plant vigor and tuber quality.
- Citrus tristeza virus (citrus): Stunts growth and reduces fruit production in infected trees.
Nematode Diseases
- Root-knot nematodes (many plants): Form galls on roots, disrupting nutrient and water uptake.
- Lesion nematodes (cereals): Cause lesions on roots, reducing root function and plant growth.
- Dagger nematodes (strawberry): Damage root systems and reduce plant vigor and yield.
- Pin nematodes (potato): Feed on stolons, reducing tuber quality and yield.
Other Diseases
- Phytophthora root rot (soybean, corn): Causes root and stem rot, leading to stunted growth and reduced yield.
- Sclerotinia rot (soybean, sunflower): Forms sclerotia on stems and pods, infecting plants in cool, moist conditions.
- Leaf scorch (tree species): Causes leaves to turn brown and drop prematurely, reducing photosynthetic capacity.
- Nutrient deficiencies (e.g., nitrogen, potassium): Can cause a variety of symptoms, including stunted growth, yellowing, and poor fruit quality.